Re: atomic_thread_fence() semantics

[Sebastian Huber <sebastian dot huber at embedded-brains dot de>]

On 19/10/17 14:18, Andrew Haley wrote:
> On 19/10/17 13:10, Jonathan Wakely wrote:
> > There are no atomic operations on atomic objects here, so the fence
> > doesn't synchronize with anything.
> Really?  This seems rather unhelpful, to say the least.
>
> An atomic release operation X in thread A synchronizes-with an acquire
> fence F in thread B, if
>
>      there exists an atomic read Y (with any memory order)
>      Y reads the value written by X (or by the release sequence headed by X)
>      Y is sequenced-before F in thread B
>
> In this case, all non-atomic and relaxed atomic stores that
> happen-before X in thread A will be synchronized-with all non-atomic
> and relaxed atomic loads from the same locations made in thread B
> after F.

Where is the acquire fence or a load in the example?

--
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